James frederick hodgetts



' (No Model.)

J. P. HODGETTS. IRON GLAD OR OTHER VESSEL.

'N0..445,345. Patented'J'an. 27,1891, W

77iinesses:

' UNITED STATES PATENT OFFICE.

JAMES FREDERICK I-IODGE' IS, OF LONDON, ENGLAND.

IRON-GLAD OR OTHER VESSELS.

SPECIFICATION forming part of Letters Patent No. 445,845, dated January 2'7, 1891.

Application filed May 13, 1890. Serial No. 351,606. (No model.)

To all whom it may concern."

Be it known that 1, JAMES FREDERICK IIODGETTS, residing atLondon, England, have invented an Improvement in Iron-Olads or other Vessels, of which-the following is a specification.

My invention relates to improvements in the construction of the bulls of iron-clads or other vessels, and is designed to provide increased resistance to submergence and greater steadiness and stability in flotation, besides other advantages, hereinafter detailed.

Vhereas the most ordinary form of sections of the hull of a vessel is round-bottomed or 'of a peg-top shape, I have found by experimental trials that many advantages accrue to a vessel, especially when required for fighting purposes, by forming the bottom and bilge of the ship by means of a pair of catenarian curves, each of the character produced by the suspension of a chain from points of different heights concave to the water (instead of the usual convex bilge) and springing from a central keel,dipping at each of the outer extremities into side keels, parallel to the center keel and of about the same depth, these curves being of greater degree of curvature at or near the side keels than near the central keel. This pair of curves presents somewhat the appearance of a pair of extended wings, such as those of the albatross, and although I specify these curves to be of the character of reverse catenarian curves, for convenient geometrical definition, similar curves may be employed-that is to say, an ycurve which springs from the central keel with an easy curve of small curvature and dips suddenly with a terminal curve of increased curvature running nearly vertically into the side keels, and such curves, being approximately similar to a catenary curve, though not an exact catenary in a strictly geometrical sense, may be used according to myinvention. I have found that this particular form of bottom gives a practical grip to the vessel of the bearing water, and thus tends to set in motion a large mass of water when the vessel tends to roll. The inertia, therefore, of the gripped volume of water would tend largely to check rolling. The outline of the hull in section is such that the transverse dimension or average beam of the hull is considerably greatest at the water line, the submerged portion receding back to th e outermost keel on either side and the upper works also receding from the Water-line to the bulwarks, and when protective armor is employed an inclined surface is presented to the impact of projectiles, and thus tends to defiect them.

It has further been found from experimental trials that the special construction of the bottom of the hull, as above described,andwith which may be combined spaces or pockets containing and retaining air, confers a great increase of buoyancy upon the vessel as compared with its apparent external displacement. This quality will therefore enable such a vessel to carry a greater weight of armor and heavier guns than is possible in ordinary hulls of ships of like tonnage. Again,

my concave construction will provide an ele-' ment of buoyancy after the external shell of the hull may have been pierced. Screws may be fitted to any of the said keels either fore or aft, which if, say four in numberviz., two on each of the outside keelswill give extra assurance against total disablement of all pro pellers and will confer great advantages upon the vessel as regards steering. The position of the propelling-screws above described will be such that they will be situated on the quarter and near the bows of the vessel, and would be thus protected by the overhanging bow and quarters of the said vessel.

In order that my invention may be the better understood, I now proceed to describe the same, reference being had to the drawings herewith, and to the letters marked thereon.

Figure 1 is a half-section of my improved vessel at amidshi'ps, showing the particular outline of the vessel at this point and showing at one side outline sections toward the bow and in the other outline sections toward the stern. Fig. 2 is aprofile view of myimproved vessel, showing how and where the concave arches gradually merge into the central keel at the stem and stern.

A is the central keel of the vessel, from which spring on each side of it the curved arches B B of a catenary or equivalent form, the archesB B terminating in the side keels c c. The sides of the ship are formed of a glacis shape, as shown at D D, the face of such glacis being covered by armor.

ICO

The interior of the vessel is divided into water-tight compartments.

The propellers are shown in convenient positions at E.

Having, now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that What I claim is The construction of the hull of a Vessel with the bottom and bilge formed by a pair of curves, such as reverse catenarian curves, in the plane of the cross-section of the vessel concave t0 the water and springing from a central keel with a curve of small curvature and dipping at their outer extremities With curves of much curvature to side keels parallel to the center keel, substantially as described. e

In testimony whereof I have signed my name to this specification in the presence of 20 t-Wo subscribing Witnesses.

JAMES FREDERICK HODGETTS.

\Vitnesses:

REGINALD W. JAMES, I RICHARD A. HOFFMANN. 

